From 985d8e62ef5f1b006da5e175858e552c0dbda771 Mon Sep 17 00:00:00 2001 From: Josh Poimboeuf Date: Mon, 18 Sep 2017 21:43:30 -0500 Subject: [PATCH 052/231] objtool: Don't report end of section error after an empty unwind hint MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit CVE-2017-5754 If asm code specifies an UNWIND_HINT_EMPTY hint, don't warn if the section ends unexpectedly. This can happen with the xen-head.S code because the hypercall_page is "text" but it's all zeros. Signed-off-by: Josh Poimboeuf Cc: Andy Lutomirski Cc: Boris Ostrovsky Cc: Jiri Slaby Cc: Juergen Gross Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/ddafe199dd8797e40e3c2777373347eba1d65572.1505764066.git.jpoimboe@redhat.com Signed-off-by: Ingo Molnar (cherry picked from commit 00d96180dc38ef872ac471c2d3e14b067cbd895d) Signed-off-by: Andy Whitcroft Signed-off-by: Kleber Sacilotto de Souza (cherry picked from commit 9d22f903bba24f2ac86de8a81dc1788f9957aca8) Signed-off-by: Fabian Grünbichler --- tools/objtool/check.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/tools/objtool/check.c b/tools/objtool/check.c index 368275de5f23..0a86fd0ac082 100644 --- a/tools/objtool/check.c +++ b/tools/objtool/check.c @@ -1652,11 +1652,14 @@ static int validate_branch(struct objtool_file *file, struct instruction *first, if (insn->dead_end) return 0; - insn = next_insn; - if (!insn) { + if (!next_insn) { + if (state.cfa.base == CFI_UNDEFINED) + return 0; WARN("%s: unexpected end of section", sec->name); return 1; } + + insn = next_insn; } return 0; -- 2.14.2